# include <iostream>

using namespace std;
void test01(){
    string str1;
    str1 ="hello world";
    cout<<"str1="<<str1<<endl;
    string str2;
   str2= str1 ;
    cout<<"str2="<<str2<<endl;
    string str3;
    str3='a';
    cout<<"str3="<<str3<<endl;
    string str4;
    str4.assign("hello c++");
    cout<<"str4="<<str4<<endl;
    string str5;
    str5.assign("hello c++",7);
    cout<<"str5="<<str5<<endl;
    string str6;
    str6.assign(str5);
    cout<<"str6="<<str6<<endl;
    string str7;
    str7.assign(20,'x');
    cout<<"str7="<<str7<<endl;
}
int main() {
    test01();
    system("pause");
    return 0;
}
